Vehicle air conditioning (A/C) systems require maintenance, which includes refrigerant recovery, evacuation, recycling and recharging of the A/C systems. The refrigerant recovery unit may be portable and may connect to the A/C system of the vehicle to recover refrigerant out of the system, separate out contaminants and oil, and recharge the A/C system with additional refrigerant.
Also, the refrigerant recovery unit may perform diagnostic tests on the A/C system of the vehicles in order to determine faults of the A/C system. Conventionally, the refrigerant recovery unit may be coupled to the A/C system of the vehicle in order to measure a pressure of the A/C system. The refrigerant recovery unit may utilize the measured pressure to troubleshoot faults in the A/C system. However, the pressure of the A/C system measured by the refrigerant recovery unit may not be accurate because the measured pressure may be significantly affected by the performance of the A/C system. For example, refrigerant may leak from the A/C system into the service hoses of the refrigerant recovery unit and thus, may cause an inaccurate diagnostic test.
For example, the pressure of the A/C system may be measured based on an amount of refrigerant that travels from the A/C system to the refrigerant recovery unit. However, the A/C system's performance may significantly affect an amount of refrigerant that travels from the A/C system to the refrigerant recovery unit and thus, affect the measured pressure of the A/C system. Therefore, a need exists for an accurate and easy diagnostic test for A/C system of vehicles using the refrigerant recovery unit.